Kedar Hiremath Andrew Floren Josh Armstrong Matt deWet Slide 2
Overview of Presentation Introduce the Configurable Laser Tag
System Design and Implementation Problems Encountered Cost and
Other Considerations Conclusion and Recommendations Questions?
Slide 3 Standard Laser Tag Simulated gun combat using infrared
beams Problems: Limited Strategy Limited Teamwork Repetitive Low
Replay Value
http://www.laser-tron.com/Laser_Tag_Library/Laser_Tag_KidsPlayingLASERTRON.jpg
Slide 4 Solution: Add Configurability! Ability to customize the
game Create different gametypes & objectives Modify behavior of
game devices Improvements: -Objective-Based Gameplay -Complex
Tactical Strategy -Teamwork Required -High Replay Value Screenshot
from Halo Capture The Flag
http://www.bungie.net/images/games/HaloPC/screenshots/halopc_deathisland_ctf.jpg
Slide 5 System Needs Basic laser tag functionality Wireless
communication across devices Game scripting system Ability to
script game Intuitive drag-and-drop GUI Robust compiler &
linker Remotely initialize all game devices Slide 6 System Needs
Ability to play indoors & outdoors Minimal power usage (max
battery life) Low consumer costs Low prototyping costs
http://www.linksengineer.com/Admin/NewsImages/479a012f-fa62-45ac-9ae3-ae40d092dd32.JPG
Slide 7 Commercial Laser TagConfigurable Laser Tag Simulated gun
combat Score Aggregation Objective-Based Play Configurable Devices
Scriptable Gametypes Feature Comparison Slide 8 Slide 9 Design
Overview Two devices necessary for basic laser tag Tagger Necessary
for tagging other players Transmits IR data Pack Necessary for
sensing when a player is tagged Receives IR data Slide 10 Design
Overview In order to meet design objectives we need two additional
devices Central Computer Keeps track of game state Enforces rules
Communicates via RF Pylon Need stationary devices for players to
interact with Functionality dependent on gametype Slide 11 Scale of
Project Four completely separate devices IR communication RF
communication USB communication Scripting language Complex software
running on all devices Slide 12 System Communication Slide 13 IR
Communications Hardware Chose matching lens diameter and focal
length Protocol Designed 23 bit IR packet Error Handling Added 6
bit hamming code for error correction TEAM IDPLAYER ID EVENT ID
40KHz Wave TSOP4840 IR Receiver TSAL6100 IR LED WPN DMG Slide 14 RF
Communication Hardware Using ONE-NET schematics Protocol Using
ONE-NET protocol Allows multiple devices to share a single channel
Uses acknowledgment packets to guarantee delivery Slide 15
Scripting System Making scripting easy Think LabVIEW or Lego
Mindstorms Basic structure Triggers & Primitives Basic logic
How do we accomplish this? Internal representation? Interpreter?
Slide 16 Scripting System Example Example C code Equivalent Syntax
Tree void takeDamage(int amount, int shooterId) { if(!isDead) { if
(HP > amount) HP = HP - amount; else { HP = 0; die(shooterId); }
Slide 17 Scripting System Example Example Syntax Tree XML
Representation Slide 18 Slide 19 Implementing Scripting Have a
back-end representation This must run on microcontrollers Need to
convert XML to executable code Slide 20 Implementing Scripting
Drag-and-Drop GUI Abstract Syntax Tree (XML) XML Parser Compiler
Linker Code Generation Slide 21 Compiler & Linker Tasks Lexical
Analysis / Parsing Preprocessing Semantic Analysis Linking within
scripts Linking between multiple scripts Code generation Fix for
microcontrollers Compiling is messy Slide 22 Compiler & Linker
Huge amount of work 4000+ lines of code Written in C++ Used only
XML parsing library Completed! Slide 23 Interpreter GUI: User-drawn
nodes XML script Compiler: XML script Data structures Interpreter:
Run data structures Slide 24 Interpreter GUI: User-drawn nodes XML
script Compiler: XML script Data structures Interpreter: Run data
structures Low level code to run on microcontrollers Control
devices based on script Primitives & Triggers Event
infrastructure Slide 25 Interpreter GUI: User-drawn nodes XML
script Compiler: XML script Data structures Interpreter: Run data
structures Programmer/Flasher? Slide 26 Remote Programming Need to
load scripts onto microcontroller via RF Central computer listens
for new devices Send initialization data Keep list of active
devices Interrupts must be disable while flashing Created packet
request mechanism
http://www.cisco.com/en/US/i/200001-300000/270001-280000/270001-271000/270121.jpg
Slide 27 Major Changes Changed wireless module to XBee Modules
pre-built Protocol nearly identical to ONE-NET Switched from
crystal oscillator to timer circuit Timer circuit far more reliable
Switched microcontrollers twice First to consolidate to a single
type of microcontroller Second to increase RAM and IO pins Slide 28
Device Design Central Computer Slide 29 Device Design - Tagger
Slide 30 Device Design - Pack Slide 31 Device Design - Pylon Slide
32 Device Casing Slide 33 Slide 34 Work Completed IR communication
Protocol, software, and hardware RF communication Software and
Hardware PCBs Pack Tagger Pylon Central Computer Slide 35 Work
Completed LCD interface High level scripting language Parser,
compiler, and linker Ability to flash compiled script Script
interpreter Remote procedural calls Slide 36 Work Remaining System
integration IR and timer code Power circuit Script gametypes GUI
for admin and scripting front end Slide 37 Problems Encountered BDM
Programmer PCB Problems Vdd and Vss Footprints Power circuit Via
sizes Slide 38 Slide 39 Hardware Testing System testing Incomplete
hardware Module testing Pack, Tagger, Central Computer, and Pylon
Component testing ICs and passives Slide 40 Demo Milestone
Protoboard Demo Tagger Pack Central Computer RF, IR, LCD All
working Slide 41 Compiler Testing Slide 42 Slide 43 Project Scale
Project was huge 12 hours per week to start 48 hours per week for
last 5 weeks Plus other classes! Slide 44 Past Costs ItemCost LCD,
10 IR Leds, 4 IR recievers$25.80 RF Parts$12.59 PCBs over the
summer$85.00 Breakout Board$12.49 PVC$12.24 USB controller$18.00 IR
mounting$88.95 Crystals for IR$13.00 Shipping costs$17.14
TOTAL$285.21 Slide 45 New Costs ItemCost Final order from
Digikey$112.00 Wires and connectors from pololu.com $141.47 Jameco
- IR circuit & various parts$30.62 Final ordered PCBs$121.70
Final order from Mouser$109.21 Final order of LCDs$39.42 RadioShack
Purchases$40.78 TOTAL$595.20 Slide 46 Cost to Others Oscilloscopes
Power supplies Countless parts checked out Resistors Capacitors
Programmer Soldering Iron Breakout boards
http://hacknmod.com/wp-content/uploads/2008/10/oscilloscope.jpg
Slide 47 Slide 48 Safety and Ethics IR safety Low power RF safety
Low power FCC approved bands Entertainment device Failure is not
dangerous http://www.laserfx.com/BasicSafety/safety.gif Slide 49
What We Learned USB communication and bus-power Send/receive
encoded IR signals Send/receive encoded RF packets Design a
language, XML parser, compiler and linker Slide 50 What We Learned
Solder SMT prototypes Efficiently design and layout circuits
Conserve space Effective teamwork Slide 51 Recommendations Do not
tear down make continual progress If possible, get components that
run on the same voltage Do not try to re- invent the wheel
http://209.169.12.51/images/products/08687-03-L_i_ma.jpg Slide 52
Recommendations Compromise between low prototype cost and low
product cost Remember: it is a prototype, not the end product
Prioritize the essential parts Do not leave the power system until
the end Slide 53 Conclusion The Configurable Laser Tag System
Introduces customizable objective-based gameplay Is a complex
integration of Configurable devices Communication protocols Game
scripting software Slide 54 Conclusion If any one subsystem is not
functioning, the system as a whole will fail to operate Despite the
problems we encountered, we learned a lot, worked hard, and
completed a significant portion of the work Slide 55
